In the field of electronics and, specifically, of motor vehicle electrical systems, there is an increasing requirement for connections between rigid printed circuit boards and flexible cables such as flat flexible circuits (or "FFCs"). Since relatively complex circuits are now constructed on flexible materials, their connection to conventional printed circuit boards has become increasingly more important.
Such connections have heretofore been effected by soldering, particularly in the case of known FFC constructions using polyimide as the flexible support material, and copper as the conductive material. Furthermore, since the conductive traces on the FFC consist of solid metal, i.e. copper, other known connection technologies, such as plug and screw contacts, can also be utilized in applications where additional mechanical stability is required.
However, other support materials are being used to an increasing extent, such as polyethylene terephthalate, and other conductive materials have been used, such as silver grains embedded in an epoxide. Although the layers of such conductive materials can have thicknesses of 5-10 mm, they do not have the strength of conventional copper conductive material, which may be needed in some applications. Furthermore, these conductive materials are thermally and mechanically sensitive, and therefore different solutions may be required for their connection to printed circuits. In particular, the reliability of these connections in the automobile industry, in relation to mechanical loadability, vibration and corrosion resistance, for example is of utmost importance.